Dayton Caps for 4396
Scott - what is the value of the Dayton's you use in your output mod for a DEQ?
Scott - what is the value of the Dayton's you use in your output mod for a DEQ?
SRC2496 Circuit Diagram
Hi,
I maybe too late to help, but I came across the circuit diagram of the SRC2496. It seems that I cannot attach it .. it is around 2MB and runs to 4 pages but I am happy to ship it to anyone that requests it.
I have a new SRC2496 and I am planning to upgrade this to the AK4396 chip and take the output directly from its pins.. essentially the same upgrade as being performed on the Sony PlayStation 1, which also uses an AK chip. Thought you might like to know this
Hi,
I maybe too late to help, but I came across the circuit diagram of the SRC2496. It seems that I cannot attach it .. it is around 2MB and runs to 4 pages but I am happy to ship it to anyone that requests it.
I have a new SRC2496 and I am planning to upgrade this to the AK4396 chip and take the output directly from its pins.. essentially the same upgrade as being performed on the Sony PlayStation 1, which also uses an AK chip. Thought you might like to know this
Did you manage to fit it in the box?
I'm planning to do the same, but would like miniature tubes (as the new lampizator version)
Hi,
a plea for advice.... I have found a company here in the UK which has offered to remove the old DAC chip and replace it with the 4396 (which I have to supply). The cost is £120. This is the only offer that i have had for this work so far. can anyone advise on cheaper (but reliable) alternatives?
Thanks
a plea for advice.... I have found a company here in the UK which has offered to remove the old DAC chip and replace it with the 4396 (which I have to supply). The cost is £120. This is the only offer that i have had for this work so far. can anyone advise on cheaper (but reliable) alternatives?
Thanks
Any repair shop
Any large local repair shop that does TVs can do that chip. Just remind the tech that these chips are easily damaged from heat.
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Do not use cathode!!!
Do not use cathode for the dac output. only uses the grid to gain signal.
cathode is dangerous that can damaged ur dac.
I contacted dr. lamp. he told me this..
Do not use cathode for the dac output. only uses the grid to gain signal.
cathode is dangerous that can damaged ur dac.
I contacted dr. lamp. he told me this..
Hi,
You could download the sch from Lampizator.
http://www.lampizator.eu/LAMPIZATOR/TRANSPORT/behringer/SRC2496.pdf
You could download the sch from Lampizator.
http://www.lampizator.eu/LAMPIZATOR/TRANSPORT/behringer/SRC2496.pdf
hI,
i don't want to take anything away from Luksas's, but that cicuit borders on "not working well at all" and "inappropriate in the highest degree".
First issue is how the DAC is terminated.
Both outputs are terminated with very different loads, this will feed straight into the powersupply and actually sounds MUCH WORSE than loading the DAC symmetrical. Trust me, I tried with a range of these kind dacs as early as 10 years ago for my "Thermionic Valve Analogue Stages for Digital Audio" article.
So, if you have a religeous reason for using both outputs from the Balanced DAC make sure you terminate them into identical loads (do that even if you use only one - unless the loads are ridiculously high).
And make sure both your forward path (which CAN be grid and cathode of a tube, just not the way Lukasz shows) have identical gain at all audio (and preferably into the MHz range).
This can be done, I just did so for a commercial product, so I'm not at liberty to disclose the circuit, but it can be done with > 40dB common mode rejection , indicating acceptable balance.
The other issue with this schematic (and also the SRPP versions Lukasz has posted with voltage output DAC's) is the ridiculous gain and thus output voltage. The tubes recommended have a gain of over 20dB or 1:10.
DAC's like the AKM, Cirrus Logic, Wolfoson Micro and most other voltage output DAC's already produce all the voltage most amplifiers need to go into clipping. Amplifying them another 10 times produces so high output voltages that many amplifiers and pre-amplifiers have problems handling the voltage and at the same time the tube stage will also show a lot of distortion, especially with the lowish supply voltages Lukasz favours.
Of course, if the result works well for you and you like the sound all is well and no need to worry, but as a warning to many DIY'ers with only a little experience, getting the best results with common voltage output DAC's from this and the SRPP circuits Lukasz posts can be a bit of a challenge.
I suspect that all else being equal using the old "super cathode follower" from my ancient Y2K Article may still be the best choice, at least until my update to this article gets published (it is written):
http://www.fortunecity.com/rivendell/xentar/1179/theory/vasfda/vasfda.html
Ciao T
i don't want to take anything away from Luksas's, but that cicuit borders on "not working well at all" and "inappropriate in the highest degree".
First issue is how the DAC is terminated.
Both outputs are terminated with very different loads, this will feed straight into the powersupply and actually sounds MUCH WORSE than loading the DAC symmetrical. Trust me, I tried with a range of these kind dacs as early as 10 years ago for my "Thermionic Valve Analogue Stages for Digital Audio" article.
So, if you have a religeous reason for using both outputs from the Balanced DAC make sure you terminate them into identical loads (do that even if you use only one - unless the loads are ridiculously high).
And make sure both your forward path (which CAN be grid and cathode of a tube, just not the way Lukasz shows) have identical gain at all audio (and preferably into the MHz range).
This can be done, I just did so for a commercial product, so I'm not at liberty to disclose the circuit, but it can be done with > 40dB common mode rejection , indicating acceptable balance.
The other issue with this schematic (and also the SRPP versions Lukasz has posted with voltage output DAC's) is the ridiculous gain and thus output voltage. The tubes recommended have a gain of over 20dB or 1:10.
DAC's like the AKM, Cirrus Logic, Wolfoson Micro and most other voltage output DAC's already produce all the voltage most amplifiers need to go into clipping. Amplifying them another 10 times produces so high output voltages that many amplifiers and pre-amplifiers have problems handling the voltage and at the same time the tube stage will also show a lot of distortion, especially with the lowish supply voltages Lukasz favours.
Of course, if the result works well for you and you like the sound all is well and no need to worry, but as a warning to many DIY'ers with only a little experience, getting the best results with common voltage output DAC's from this and the SRPP circuits Lukasz posts can be a bit of a challenge.
I suspect that all else being equal using the old "super cathode follower" from my ancient Y2K Article may still be the best choice, at least until my update to this article gets published (it is written):
http://www.fortunecity.com/rivendell/xentar/1179/theory/vasfda/vasfda.html
Ciao T
Some are addicted to tubes just because it is something "different". But that "different" is not "better" in most of the cases.
Before trying to mod with tubes your DAC's try to use a decent, last generation OpAmp. Most of the manufacturers use cheap OpAmps to lower the BOM, even on hi-end devices.
In my opinion the schematics used by Lucasz are bad designed, will have lots of distorsions, lots of HF garbage pushed into the amplifier, too high of a gain. It cannot sound right, even if some people will say that. Some hear what they want to hear, not what really comes out from the speakers. And that's ok too... for them.
Before trying to mod with tubes your DAC's try to use a decent, last generation OpAmp. Most of the manufacturers use cheap OpAmps to lower the BOM, even on hi-end devices.
In my opinion the schematics used by Lucasz are bad designed, will have lots of distorsions, lots of HF garbage pushed into the amplifier, too high of a gain. It cannot sound right, even if some people will say that. Some hear what they want to hear, not what really comes out from the speakers. And that's ok too... for them.
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Hi,
Not sure about that. Well designed Tube circuitry is excellent sonically and generally "better", not just different.
In the case of the Behringer Gear often used by DIY'ers and in home audio (that is SRC2496, DEQ2496 and DCX2496) the original analog stage is about as bad a design as that with tubes (and I am not even talking about too much gain).
So not only is replacing the Op-Amp's with dirrerent ones a major PITA (all SMD), afterwards the design is still very bad.
So replacing the analog stage wholesale is usually a good idea for these devices, even using tube stages (ones that work correctly of course, like a commercial product I recently designed).
Ciao T
Not sure about that. Well designed Tube circuitry is excellent sonically and generally "better", not just different.
In the case of the Behringer Gear often used by DIY'ers and in home audio (that is SRC2496, DEQ2496 and DCX2496) the original analog stage is about as bad a design as that with tubes (and I am not even talking about too much gain).
So not only is replacing the Op-Amp's with dirrerent ones a major PITA (all SMD), afterwards the design is still very bad.
So replacing the analog stage wholesale is usually a good idea for these devices, even using tube stages (ones that work correctly of course, like a commercial product I recently designed).
Ciao T
I have looked over various I/V stages with tubes posted here on the forum and just a few where proper designed in my oppinion. Sure, I can be wrong.
I did listen to one of those DAC's with tubes (eBay one) and it didn't sound better than what I have in my Denon receiver (after I swaped the OpAmps). SMD is a PITA but for me was easier than providing a good High Voltage supply (plus the heater one) in the receiver.
Your article is very well written (even if is biased somehow
). Even there, the second circuit (one with differential voltage inputs) doesn't make me feel confident that will sound better than a LT1028 or a LME49990 (or something like that). Plus the "-" side is connected to nothing as it is drawn.
I did listen to one of those DAC's with tubes (eBay one) and it didn't sound better than what I have in my Denon receiver (after I swaped the OpAmps). SMD is a PITA but for me was easier than providing a good High Voltage supply (plus the heater one) in the receiver.
Your article is very well written (even if is biased somehow
). Even there, the second circuit (one with differential voltage inputs) doesn't make me feel confident that will sound better than a LT1028 or a LME49990 (or something like that). Plus the "-" side is connected to nothing as it is drawn.
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